In recent, according to advances in car industry, automobile supply is commercialized such that one household owns one car, and drivers who drive a long distance greatly increase thanks to expansion of expressway and road transportation system. Accordingly, truck drivers having frequent long-distance transportation and long-distance commuters are exposed to a danger of a lane departure accident due to fatigue, carelessness, and drowsy driving caused by long-distance driving.
Generally, Advanced Safety Vehicle (ASV), which is an advanced vehicle applying high electronic technology and control technology to enhance safety of the vehicle, increases the volume of traffic by reducing car accidents, conserves energy, and promotes driver's convenience.
The ASV includes Adaptive Cruise Control (ACC) which automatically controls a distance between vehicles, and Lane Departure Warning System (LDWS) which monitors and warns of lane departure.
Particularly, the LDWS is a safety system which detects the current lane by sensing a front-road image from a camera attached to the vehicle and sounds an alarm when the driver departs the lane due to carelessness or drowsy driving. The LDWS synthetically analyzes a lateral position, a lateral speed, a steering angle, a width of the lane, and a curve of the road based on the image captured by the camera, and informs the user when detecting the lane departure according to the analysis result.
A conventional method detects the lane departure by extracting the lane from the left and right images of the rear side captured by the camera mounted to both side mirrors of the vehicle and calculating the angle formed by the extracted left and right lanes and the direction line of the vehicle. Another conventional method determines the lane departure by recognizing the lane from the front image and the road image captured by the camera mounted to the front of the vehicle and extracting a slope change of the recognized lane.
However, the conventional methods simply combine and display the left and right images of the vehicle and thus cannot accurately determine the current location of the vehicle or the lane departure degree because they do not naturally overlay the images. In particular, it is hard to accurately determine the departure degree of the current vehicle merely with the front image of the vehicle and the driver has difficulty in easily checking the driving condition.